Disconnecting fuse switch



May 24, 1938. w. o. SCHULTZ ET AL.

DISCONNECTING FUSE SWI-TCH Filed June 9, 1934 2 Sheets-Sheet l ATTORNEYy 3 w. o. SCHULTZ ET AL 2,118,270

DISCONNECTING FUSE SWITCH Filed June 9, 1954 2 Sheets-Sheet 2 INVENTORBY WM ATTORNEY Patented May 24, 1938 UNITED STATES PATENT OFFICEDISCONNECTIN G FUSE. SWITCH William 0. Schultz, South Milwaukee, andAlwin G. Steinmayer, Milwaukee, Wis., assignors to Lin Material Company,

South Milwaukee,

This invention relates to disconnecting fuse switches.

It is the principal object of this invention to provide an open typedrop out fuse in which the fuse tube is pivotally supported from a lineterminal for movement into engagement with projecting horn-like contactssupported from a second line terminal, the horn contacts being adaptedto force the fuse tube to an open position when the fuse blows and todelay disengagement from the horn contacts during the time that the fuseis blowing.

It is another object to provide adjustable horn contacts which may beadjusted relative to the terminal supporting it in order to give thedesired tension to the horns for engagement with the fuse tube contact.

It is also an object to provide an adjustable contact for switches whichis adapted for use in connection with any one of a plurality ofinsulator support assemblies.

It is also an object to provide for drop out fuses, latch mechanism inwhich the contact arrangement acts as a portion of the latch mechanismfor securing the fuse tube in closed position and adapted to release thefuse tube for movement to open position when the fuse blows, saidcontact being adjustably mounted on its support to thereby obtain adesired latching tension serviceable to move the tube to open position.

Still another object is to provide resilient contact horns in which themaximum resilient strength may be utilized to secure a correspondingmaximum contact of the horns with a fuse terminal contact.

A further object of this invention is to provide a pivot for the fusetube which may serve as a connector and thus eliminate, as far aspossible, all joints between the conductor and the fuse link.

It is also a further object to provide a novel pivotal mounting for afuse tube comprising a connector and terminal for electrical conductors.

Other objects will become apparent as the description proceeds.

In the drawings,

Fig. 1 is a view in side elevation showing an embodiment of thisinvention.

Fig. 2 is a fragmentary view taken on the line 50 22 of Fig. 1.

Fig. 3 is an enlarged detailed sectional view taken on the line 3-3 ofFig. 1. v

Fig. 4 is a view in perspective similar to Fig. 1 showing a modifiedform.

Fig. 5 is an enlarged view taken on the line 5-5 of Fig. 4 showing theparallel arms of the upper contact.

Fig. 6 is a view similar to Fig. 3 showing a modified form of pivot andconnector for the fuse cartridge.

Throughout the several views, like parts are identified by like numbers.

In Figure 1 the supporting insulator l0 comprises a single cylindricalmember providing spaced portions or cylindrical areas II and 12 on itsperiphery for terminal supports and an intermediate portion orcylindrical area l3 for engagement with the supporting means(subsequently described) attached to the crossarm I4. The supportingmeans for the insulator I0 comprises a band member l5 having a clampingbolt l6 which secures the band upon the portion l3 of the insulator, aswivel arm l8 secured by bolt I! to the member l5, and fiat bars 20, 2|,and 22, theswivel arm I8 being secured between the adjacent ends of thebars 20 and 2| by means of bolt IQ for angular adjustment of the arm I8laterally relative to the crossarm H. The bar 22 and bolts -23 and 24secure the bars 20 and 2| about the crossarm l4.

A lower terminal support 30 embraces the area l2 on the cylindricalinsulator l0 and is secured thereto by means of a bolt 3|. The terminalsupport is provided with a projecting portion 32 upon which is mounted afiat terminal supporting arm 33 secured thereto by means of bolt 34. Theterminal supporting arm is provided at its lower end with a sleeveportion 35 receiving a tubular connector pivot 36. The connector pivot36 serves a twofold purpose, namely, as a pivot for the fuse tube 31 andas a connector adapted to receive the ends of conductors to be clampedtherein by means of the set screws 38. These set screws screw into thesleeve portion 35 and through pivot 36 to serve as means for retainingthe connector pivot 36 within the sleeve portion 35 of the terminalsupport 33, and for engagement with the ends of electrical conductorsplaced in the connector pivot.

The pivotal support for the tube 31 comprises a support member 40secured to the tube and having pivot arms 4|, a pivot pin 42 supportedby the arms 4|, and contact arms 43 pivotally supported by the pivot pin42 and pivotally mounted on the connector pivot 36. As will be noted,the contact arms 43 are provided with fingers 44 which hook around theconnector piv- 0t and are adapted for removal therefrom. The contactarms 43,are also provided at a point remote from the pivot 42 andconnector pivot 36 with a terminal support l5 having a terminal nut iiiwhich clamps the flexible end ill of the fuse link to the contact arms1-3.

The other end of the fuse link is secured. in the usual manner (notshown) to the upper contact iii mounted on the tube Sll, by means of acap 5i provided with a centrally located contact pin 52 projectingupwardly between the horns The pin as shown, is tapered outwardly fromthe cap til, thus presenting a wedge-like member acting upon theportions of the horns 53 and tending to move the horns in a verticaldirection as well as laterally of each other.

The horns 53 comprise a single piece of heavy wire bent to formsubstantially parallel portions 5 1 in spaced relation throughout thelength of the horns, except at wherein the parallel portions are bentlaterally inwardly of each other to engage the pin 52 between them, andbent laterally outwardly at 5% to provide a guideway or guiding meansfor directing the pin 52 into the space between the horns and in contactwith the horns. When the fuse tube is moved about the connector pivot toclose the circuit, the pin will engage the portions 56 of the horns andbe directed thereby into contact with the portions thereof. The hornsare also bent as illustrated in Figure l to provide an upwardlyprojecting portion 5'? and a downwardly curved portion 58. To increasethe frictional engagement of the horns with the pin a clamp 66 isprovided comprising a pair of plates receiving the parallel portions ofthe horns between them and bolted together by means of bolt Thus, thelength of the spreadable portions of the arms may be predetermined forthe purpose of obtaining a desired tension by placing the clamp itproperly in relation to the ends of the horns.

The position assumed by the horns after the fuse blows is illustrated inbroken lines in Figure 1. This is the position which they assume whenthe fuse tube is in the broken line position illustrated in Figure l,which is the position taken by the fuse tube after the fuse link hasblown.

The contact horns are secured to the terminal support 65 by means of abolt 66 which passes thru the terminal support 65, between the parallelportions 5 of the horns, and through the connector plate bl. Theconnector plate is provided with a tubular portion G8 adapted to receivethe bared ends of conductors to be clamped therein by means of the setscrews 69. The terminal support 65 embraces the portion it on theinsulator iii and is secured thereto by means of a bolt lil.

From the foregoing descriptions it will appear that when the fuse linkis severed, the tube 3? will be free to move about the pivot 62 andconnector pivot by reason of the fact that the flexible end ll! will bewithdrawn from the tube when the contact lever d3 moves about theconnector pivot 3b and the tube 31 moves about the pivot $2. This actionis caused by reason of the fact that horns press downwardly upon the cap5i and thus force the tube 37] to move endwise. When the pin 52 hasmoved from between the horns 53, the corresponding end of the fuse tubemay then drop vertically about the pivots until the several parts reachthe relative positions illustrated in broken lines in Fig. 1. Thewedgelike action of the pin 52 will tend to overcome the action of thehorns in moving the tube 37! to open position after the fuse link W issevered. In other words, when the horns have moved downwardly to theirlimit of movement, the presaiiaaro sure of the portions 55 upon the pin52 will tend to move the pin downwardly. At least, the tapered shape ofthe pin 52 will permit ready withdrawal of the pin from the horn.

When it is desired to re-fuse the tube, the tube may be disengaged fromthe connector pivot 36 by means of an appropriate tool not shown)engageable with the tongue l6 on the support iil. The cap bl may then beremoved so that the remainder of the blown fuse may be taken from thetube and a new fuse link inserted thereinto and the cap then replaced tosecure the upper end of the fuse link in position in the usual manner(not shown). The flexible portion of the old fuse may be removed fromthe terminal support 15 by manipulating the terminal nut 46, and theprojecting end of the new fuse may then be secured to the terminalsupport by appropriate manipulation of the nut 6. When the flexible Iend of the fuse link is properly secured to the terminal support 85, thesupport will be brought into engagement with the tube and held there byreason of the engagement of the link as illustrated. Thus the contactarms are held against pivotal movement about the pin 32. When the fuselink has been replaced as described, the fuse may be again mounted, asillustrated, upon the connector pivot 36 and moved thereabout until thepin is positioned, as illustrated, between the parallel portions of thehorns.

The modified form shown in Figure l, insofar as the drop out fuseconstruction is concerned, is similar to that previously described. Thedif ference applies principally to the insulator mounting. In thismodified form, two insulators Sil and ill are provided in spacedrelation and connected by means of a bolt 32 upon which is mounted apair of nuts 83 and These nuts secure the swivel arms 235 and B6 toadjacent insulators. intermediate portions and are spaced at their endsremote from the insulators to receive the ends of plates 2b and 2H towhich they are secured by means of a bolt M.

The lower insulator (it is provided with a nut and bolt 9d for securingthe terminal support t l to the insulator. The terminal support bl islike that illustrated in Fig. i with the exception, that the portionthereof which is secured to the insulator is changed in angle to meetthe differmi ence in insulator construction.

The upper insulator Sb is provided with a nut and bolt 92 receivedbetween the parallel portions of the horns and clamping these portionsto the insulator. The terminal connector or clamping plate 93 islikewise clamped to the horns and insulator. The terminal plate 93 isprovided with a tubular portion 9H for receiving the bared ends ofelectrical conductors to be clamped therein by means of the set screws95.

It will be noted that the horns in Fig. 1 are clamped to the terminalsupport 65 at their vertical portions 57, whereas in Fig. 4 the hornsare clamped to the insulator fill at the portions 96 projectingsubstantially vertically from the portion 577. Thus, it becomes apparentthat the horns are adapted for use in connection with more than one typeof insulator support without altering their structure.

Attention is particularly directed to Fig. 1 in which the verticalportions 571 of theprongs, or horns, are attached to the insulator bymeans, of the terminal plate fil and bolt 86 engaged with the band E5.The portions 5i may be secured to the band 65 in any one of a pluralityof positions The swivel arms contact at their vertically relativethereto. Thus, the pressure which the prongs exert upon the cap 5|, maybe horns upon their support will not be as great for a given movement ofthe horns as in the structure shown in Fig. 1. In other words, as theportions 96 are moved longitudinally of their axes from the positionshown, the contact portions of the horns 53 will be moved relativelynear the pivot 36. This adjustment will compensate for differences ineither the length of the insulator or the tube.

It is again desired to direct attention to the action of the horns inlatching the fuse tube 31 in position. After the fuse tube has beenrefused and placed upon the pivot 36, the handle I5 will be engaged byan appropriate tool (not shown) to move the pin 52 into contact with thediverging ends 56 of the horns. Further movement of the pin willseparate the adjacent portions of the horns laterally until the pinreaches the space between the horns and beyond the relatively convergingportions thereof. When the pin reaches the position shown in Fig. 1, theends of the horns will return to their normal position and retain thepin and tube against pivotal movement about the pivot 36 until the fuseblows. During the latching movement as above indicated, the prongs ofthe horns 53 frictionally contact the end of the cap SI and thus producea wiping effect upon the contacting surfaces, thereby cutting to aminimum the resistance to electric current passing thru the joint.

The modified form of the pivot pin shown in Fig. 6 comprises a rod I00encircled by the supporting arm 33 and secured thereto by means of theset screw 38 passing thru the arm 33 and into the annular groove IOIupon the outer periphery of the rod I00. The rod is provided at each endwith axially extending arms I02 to which electrical conductors may besecured as follows: Upon the arms I02 may be mounted a connector of anysuitable design adapted to engage the arm I02 and clamp thereto aconductor I03. The connector shown in Fig. 6 is similar to thatdisclosed in the application of William D. Kyle and Clarence J. Lemont,Serial No. 701,764, filed December 11, 1933. The connector showncomprises a bifurcated threaded jaw member I04 to which is threaded anut I05 which presses the clamping jaw I06 into engagement with the wireI03 to force it against the arm I02 which extends into the bifurcatedjaw member I04. The details of the connector are not, as far as theinvention in the present case is concerned, of any importance, theconnector shown serving only to illustrate the manner in which aconductor may be connected to the pivot pin or rod I00.

As illustrated, the rod I00 extends beyond the support 33 to providepivot ends I01 upon which the fingers M of the contact arms are mountedfor pivotal movement. From the foregoing description of Fig. 6, itbecomes apparent that the number of contact surfaces between theconductor I03 and the contact arms 43, have been reduced to a minimum,thereby minimizing the resistance to the flow of electric currenttherethru.

I claim:

1. In a disconnecting switch, an insulating support, terminals mountedon said support, and a switch member pivotally mounted on said supportfor connecting said terminals, in combination with a pair of resilientcontact arms in parallel relation, and a clamp connecting said armsintermediate their ends and movable relative thereto whereby the tensionof said arms resisting lateral movement may be varied.

2. In a disconnecting switch, a contact terminal comprising a singlepiece of resilient wire bent intermediate its ends to form spacedsubstantially parallel arms disposed in a common plane and having a partconverging toward each other in said plane and then diverging toward theends of the wire, the diverging portions of the arms being disposed atan angle relative to the plane of said convergence.

3. In a disconnect switch including a support, a terminal contactthereon, and a switch member engageable with said contact; a pivot pincarried by said support and upon which said member is movably mounted,in combination with means on said pin for connecting an electricalconductor directly with said pin, whereby to provide a minimum number ofcontact joints between said conductor and switch member.

4. In a disconnect switch including a support, a terminal contactthereon; a switch member engageable with said contact in combinationwith a pivot pin carried by said support, a link pivotally connectedwith said member and movably mounted on said pin, and means on said pinfor connecting an electrical conductor directly with said pivot pin.

5. In a disconnecting switch, the combination with an insulatingsupport, of a bolt on said insulator, a contact comprising a wire bentintermediate its ends to provide substantially parallel arms receivingsaid bolt between them, a clamping plate apertured to receive said bolt,a nut holding said plate in clamping relation to said arms, said platehaving an integral portion comprising a tubular connector portion forreceiving the bared end of an electrical conductor, and clamping screwsextending into said tubular connector portion transversely to the axisthereof,

whereby the contact may be adjusted longitudinally of its arms.

6. In a disconnecting switch, the combination with an insulating supporthaving a bolt and nut thereon, of a contact comprising a Wire bentintermediate its ends to provide substantially parallel arms embracingsaid bolt, thereby to permit adjustment of said contact longitudinallyof said arms a clamping plate apertured to receive said bolt and toreceive the ends of electrical conductors, set screws on said plate forengaging the ends of said conductors, said plate being held inengagement with said arms.

7. In a disconnecting switch, the combination with an insulating supporthaving a bolt and nut thereon, of a contact comprising a wire bentintermediate its ends to provide substantially parallel arms embracingsaid bolt, a clamping plate apertured to receive said bolt and toreceive the ends of electrical conductors, set screws on said plate forengaging the ends of said conductors, said plate being held inengagement with said arms, and a clamp connecting said arms at a pointremote from the insulator and spaced from the ends of the arms, saidclamp being releasable for movement lengthwise of said arms, thereby tochange the tension of said arms resisting lateral spreading thereof.

8. As a new article of manufacture, a contact for disconnectingswitches, said contact comprising a single piece of wire bentintermediate its ends to form substantially parallel arms disposed in acommon plane, at least one of said arms having a portion converging insaid plane toward the other arm and then diverging therefrom to its endthe diverging portions being disposed angularly relative to the plane ofcorn vergence.

9. As a new article of manufacture, a contact for disconnectingswitches, said contact comprising a single piece of wire bentintermediate its ends to form substantially parallel arms, at least oneof the arms having a portion converging toward the other, and a clampconnecting said arms to hold them normally in parallel relation, saidclamp being releasable for movement lengthwise of said arms, thereby tochange the tension of said arms resisting lateral spreading thereof.

10. In a disconnect switch, a single piece of wire bent intermediate itsends to form substantially parallel arms, at least one of the armshaving a portion converging toward the other and then divergingtherefrom to its end, and a clamp connecting said arms to hold themnormally in parallel relation.

11. In a disconnect switch, a single piece of wire bent intermediate itsends to form substantially parallel relatively spaced arms, said armseach having an intermediate arcuate portion and being bent at a pointadjacent the arcuate portion to form a mounting section extendingradially outwardly relative to the arcuate portion.

12. In a disconnecting switch having an insulating support and a movableconnecting memher, a pivot supporting said member from said support andcomprising a tube for receiving the ends of electrical conductors to besecured therein, and clamping screws for securing the conductorstherein.

13. In disconnecting switch, the combination with a support and amovable connecting member pivotally mounted on said support, said memberhaving a contact finger projecting from its end, of a contact comprisinga pair of spaced resilient arms disposed in a common plane andfrictionally engaging said finger, at least one of said arms having aportion converging in said plane toward the other arm and a portiondiverging from said plane and from said parallel relationship to the endof said arm, whereby to guide said finger to a position between the armsto be latched therein.

14. In a disconnecting switch, the combination with a support and amovable connecting member pivotally mounted on said support, said memberhaving a contact finger projecting from its end, of a contact comprisinga pair of spaced resilient arms disposed in a common plane andfrictionally engaging said finger, at least one of said arms having aportion converging in said plane toward the other arm, and a clampsecuring said arms in given parallel relation at a point spaced fromsaid converging portion.

15. In a disconnecting fuse switch, an insulating support, a fuse tubehaving a fuse link projecting therefrom, a terminal mounted on saidsupport, said terminal including a hollow pivot pin adapted to receivethe ends of electrical conductors to be clamped therein and clampingscrews on said pin, said tube being pivotally supariaavo ported by saidpin with said fuse link in electrical connection therewith, and a secondterminal mounted on said support and engageable by said tube.

16. In a disconnecting fuse switch, an insulating sup-port, a, fuse tubehaving a fuse link projecting therefrom, a terminal mounted on saidsupport, said terminal including a hollow pivot pin adapted to receivethe ends of electrical conductors to be clamped therein and clampingscrews on said pin, a link pivotally supported by said pin and pivotallyconnected with said tube, said fuse link being releasably secured tosaid link, and a second terminal mounted on said support, and engageableby said tube.

U. in a disconnecting fuse switch including an insulating support,terminals mounted on said support, and a fuse tube having a fuse linkfor connecting said terminals, a pivotal mounting comprising a hollowpin on one of said terminals adapted to receive the ends of conductorsto be secured therein, a link pivotally secured to saidtube andpivotally mounted on said pin, said link having an arm to which the fuselink is secured.

18. In a disconnecting fuse switch including an insulating support,terminals mounted on said support, and a fuse tube having a fuse linkfor connecting said terminals, a pivotal mounting comprising a hollowpin on one of said terminals adapted to receive the ends of conductorsto be secured therein, a link pivotally secured to said tube andpivotally mounted on said pin, said linli: having an arm to which thefuse link is secured, and a resilient contact on the other of saidterminals urging said tube endwise to ward the direction of said pin.

19. In a disconnect switch including a support, the combination with afuse tube open at one end and closed at the other end by a cap having apin integrally therewith projecting axially of the tube, of a pivotcarried by the support and upon which the open end of the tube ismounted, and a contact carried by said support and comprising a pair ofwire prongs extending substantially relatively parallel and havingconverging portions disposed about said pin to latch the fuse tube incircuit closing position, said wire prongs having their ends divergingto provide guiding surfaces for directing said pin past said convergingportions, and said prongs being tensioned to exert pressure on said captoward said pivot and also against the sides of said pin.

20. In a fuse switch having a pivotally mounted switch member, a pivotfor said switch member, said pivot comprising a supporting arm having atubular portion, a tube extending through said portion and providingpivot bearings for said member, and a set screw extending through saidportion and through said tube, whereby to secure the tube in positionand to secure the end of an electrical conductor in said tube.

21. In a fuse switch having a pivotally mounted switch member, a pivotfor said switch member, said pivot comprising a supporting arm having atubular portion, a pivot pin extending through said portion to providepivots for said member, and means for securing said pin to said supportand a conductor directly to said pin.

22. In a fuse switch, the combination with a support, of a fusecartridge pivotally mounted on said support and having a contact surfacenormal to the axis of the tube, and a flexible con tact frictionallyengaging and pressing on said surface toward said pivot, said contactbeing slidably adjustable on and secured to said support for movement ina direction laterally vertical relative to said pivot, whereby to varythe frictional pressure of said contact on said cartridge.

23. In a fuse switch, the combination with a support provided with apivot, of a switch member mounted on said pivot and having a contactsurface normal to the longitudinal axis of the switch member, a flexiblecontact frictionally engaging said contact surface of said member andpressing on said surface toward said pivot, and means securing saidcontact to said supports and releasable to permit adjustment of saidcontacts toward said pivot, said contact having elongated spacedportions, and said means comprising a bolt extending through the spacebetween said portions and a plate held in clamping engagement with saidportions by means of said bolt, said portions extending beyond saidplate laterally of said pivot to permit adjustment relative to the pivotthereby to vary the pressure of said contact on said switch member.

24. A resilient contact for disconnecting switches, said contactcomprising a length of wire bent intermediate its ends to form a pair ofsubstantially parallel relatively spaced arms, said arms havingintermediate arcuate portions,

clamping portions between one end of said arms and said arcuate portionsdisposed radially out wardly of said outward portions, portions bentoutwardly relative to at radial direction relative to said arcuate ortsand converging in part relative to each other to constitute a latch.

25. In a disconnect switch, the combination of an insulating support, atubular fuse cartridge pivotally mounted at one end on said support, acontact carried by the support and comprising a pair of spacedsubstantially parallel arms resiliently movable towards the pivotalmounting of said tubular fuse cartridge, a terminal cap closing theother end of said tubular fuse cartridge and having a contact pinintegral there- With and projecting substantially axially of saidtubular fuse cartridge to be received between said arms, said capproviding a bearing surface for said arms extending radially of the pin,said tubular fuse cartridge being supported in a vertical position andsaid arms pressing downward- 1y on the said cartridge when the cartridgeis in circuit closing position.

WILLIAM O. SCHULTZ. ALWIN- G. S'I'EINMIAYER.

